integral of 1/(1+sqrt(1+x))

解答

\int \frac{1}{1 + 1 + x} d x

- 2 ln x + 1 + 1 + 2 x + 1 + 2 + C

求解步骤

\int \frac{1}{1 + 1 + x} d x

\frac{1}{1 + 1 + x} = - \frac{x + 1}{1 + 1 + x} + 1

= \int - \frac{x + 1}{1 + 1 + x} + 1 d x

使用积分加法定则:

\int f (x) \pm g (x) d x = \int f (x) d x \pm \int g (x) d x

= - \int \frac{x + 1}{1 + 1 + x} d x + \int 1 d x

\int \frac{x + 1}{1 + 1 + x} d x = x + 2 ln x + 1 + 1 - 2 x + 1 - 2

\int 1 d x = x

= - (x + 2 ln x + 1 + 1 - 2 x + 1 - 2) + x

化简

= - 2 ln x + 1 + 1 + 2 x + 1 + 2

解答补常数

= - 2 ln x + 1 + 1 + 2 x + 1 + 2 + C

\int - 1 - x^{2} d x

\int \frac{1}{2 x - 3 + 1} d x

\int \frac{sin ( 2 x )}{cos ( 2 x )} d x

\int \frac{x ^{2}}{( 1 - x ) ^{100}} d x

\int x ln (\frac{1 + x}{1 - x}) d x